Question

It is easier to cut with a sharp knife than with a blunt one. Explain.

Answer 1

It is easier to cut with a sharp knife than with a blunt one because, for the same applied force, the pressure exerted (force/area) is more in the case of the sharp knife than in the case of a blunt one.

Answer 2

We know that Pressure is inversely proportional to area.

So, a smaller area will exert more pressure, thus a sharp knife has a small area that comes in contact with the object, so more pressure can be applied on the object. Whereas a blunt knife has more area than a sharp knife and the pressure exerted by the blunt knife will be less as compared to that of a sharp knife.

Therefore it becomes easy to cut objects with a sharp knife than a blunt knife.